JPS60249664A - Fuel injection pump - Google Patents

Fuel injection pump

Info

Publication number
JPS60249664A
JPS60249664A JP10707084A JP10707084A JPS60249664A JP S60249664 A JPS60249664 A JP S60249664A JP 10707084 A JP10707084 A JP 10707084A JP 10707084 A JP10707084 A JP 10707084A JP S60249664 A JPS60249664 A JP S60249664A
Authority
JP
Japan
Prior art keywords
fuel
valve
pressure
valve body
passage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP10707084A
Other languages
Japanese (ja)
Other versions
JPH0256511B2 (en
Inventor
Hidehiro Tokita
時田　栄寛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kubota Corp
Original Assignee
Kubota Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kubota Corp filed Critical Kubota Corp
Priority to JP10707084A priority Critical patent/JPS60249664A/en
Publication of JPS60249664A publication Critical patent/JPS60249664A/en
Publication of JPH0256511B2 publication Critical patent/JPH0256511B2/ja
Granted legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
    • F02M59/46—Valves
    • F02M59/462—Delivery valves

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

PURPOSE:To prevent securely the secondary injection of fuel by absorbing the pressure wave generated in a fuel supply pipe at the end of fuel injection so as to suppress the internal pressure rise in the fuel supply piee by means of receding displacement of a valve body for backward flow installed in a discharge valve. CONSTITUTION:In a fuel injection pump 3, when pressurization of fuel is carried out, a discharge valve 9 lifts against the force of a spring 8 and a valve body 12 fitted on the spindle 9a of the discharge valve disc 9 passes through the valve seat, and therefore pressurized fuel is fed to a discharge passage 10. When the fuel feed under pressure finishes, the discharge valve 9 is pressed back downward by the spring 8 to hit and contact with the valve seat, and closes the valve. In this case, if any pressure wave is generated in a fuel suply pipe communicating with the discharge passage 10, the pressure acts on the valve body 12 through a passage 11 and accordingly the valve body 12 is lowered against the force of spring 13 to absorb the pressure. Furthermore, if the pressure wave is significantly strong, the valve body 12 recedes to a large extent to exceed the ports 17a in the spindle 9a, thus the pressure is relieved through the passage 11, ports 17a and a passage 17.

Description

【発明の詳細な説明】 〈産業上の利用分野〉 この発明は、ディーゼルエンジンに用いられる燃料噴射
ポンプに関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a fuel injection pump used in a diesel engine.

〈従来技術〉 ディーゼルエンジンにおいては、燃料の完全燃焼を行わ
せるために、燃料噴射系統に噴射後期における“あとだ
れ”を防止した燃料噴射の切れをよくした特性が要求さ
れる。このような特性を得るために、従来は噴射ポンプ
のプランンヤ径を大きくし、かつ、噴射ノズル側に装備
した噴射弁の開弁圧を高くして、高圧の燃料を短時間に
噴射することが行われていた。<Prior Art> In a diesel engine, in order to achieve complete combustion of fuel, the fuel injection system is required to have characteristics that improve the sharpness of the fuel injection and prevent "drip" in the later stages of injection. In order to obtain such characteristics, conventionally, the plunger diameter of the injection pump was increased and the opening pressure of the injection valve installed on the injection nozzle side was increased to inject high-pressure fuel in a short time. It was done.

〈発明が解決しようとする問題点〉 しかし、高圧噴射を行うと、噴射終了後に燃料供給管内
に生じる圧力波が噴射ポンプに内装した送出弁とノズル
との間を往復し、ノズルの噴射弁を僅かに再び開き、二
次噴射をもたらす問題があった。<Problems to be solved by the invention> However, when high-pressure injection is performed, the pressure waves generated in the fuel supply pipe after the end of injection reciprocate between the delivery valve built into the injection pump and the nozzle, causing the injection valve of the nozzle to There was a problem with it opening slightly again, resulting in a secondary injection.

この発明は、ポンプ内の送出弁部に改良を加えることで
供給管内の反射波吸収を可能にして二次噴射の発生を防
止できるようにしたものである。This invention makes it possible to absorb reflected waves in the supply pipe by improving the delivery valve section in the pump, thereby making it possible to prevent the occurrence of secondary injection.

〈問題を解決するための手段〉 このために、本発明では、閉弁付勢された送出弁に燃料
供給管側からの燃料逆流を許す流路を形成するとともに
、送出弁閉弁状態における供給管内圧上昇に伴って後退
移動して送出弁内−の燃料逆流を許す逆流用弁体を送出
弁に設けた構造を採用した。<Means for Solving the Problem> To this end, in the present invention, a flow path is formed in the delivery valve that is biased to close, allowing backflow of fuel from the fuel supply pipe side, and the supply valve is forced to close when the delivery valve is closed. A structure is adopted in which the delivery valve is provided with a backflow valve element that moves backward as the pressure inside the pipe increases, allowing fuel to flow back into the delivery valve.

〈作　用〉 送出弁か閉した状態で燃料供給管の内圧が上昇するにつ
れて逆流用弁体が後退されで、送出弁の流路な通して弁
内に燃料が流入し、燃料供給管の内圧士別か抑制される
。<Function> As the internal pressure of the fuel supply pipe increases with the delivery valve closed, the backflow valve body is moved back, and fuel flows into the valve through the flow path of the delivery valve, causing the internal pressure of the fuel supply pipe to decrease. Shibetsu is suppressed.

〈実施例〉 第１図に燃料噴射系の全体が示される。燃料タンク１の
燃料はフィルター２を経て噴射ポンプ３に供給される。<Example> FIG. 1 shows the entire fuel injection system. Fuel in a fuel tank 1 is supplied to an injection pump 3 via a filter 2.

ポンプ３はカム４によって間欠的に駆動され、フントロ
ールラック５で調節された流量の加圧燃料が供給管６を
介して噴射ノズル７に圧送される。The pump 3 is driven intermittently by a cam 4, and pressurized fuel at a flow rate regulated by a fuel rack 5 is fed under pressure to an injection nozzle 7 via a supply pipe 6.

第２図に示すように噴射ポンプ３の送出部には燃料加圧
によって開動し、バネ８によって閉動する送出弁９が設
けられている。この送出弁９の上部には供給管６に通じ
る送出路１０から弁内への燃料逆流を許す流路１１が形
成されるとともに、送出弁９から下方プランジャー側に
延出した軸部９ａに、上記逆流用流路１１よりも下方に
おいて上下動自在なカラー状の弁体１２か装着されてい
る。この弁体１２は、バネ１３で軽く上方に付勢される
とともに、その上限か軸部９ａに設けた段部１４によっ
て規制されている。又、軸部９ａの下端には上記バネ１
３の下端を受けるカラー１５が取付けられるとともに、
軸部９ａの下半部にバネ室１６と下方のプランジャー側
とを連通する流路１７が形成され、がっ、この流路１７
は弁体１２が一定以上下方に後退移動されると、上記逆
流用流路１１に連通するよう上端開口１７ａが形成され
ている。As shown in FIG. 2, the delivery portion of the injection pump 3 is provided with a delivery valve 9 that is opened by pressurizing the fuel and closed by a spring 8. A passage 11 is formed in the upper part of the delivery valve 9 to allow fuel to flow back into the valve from a delivery passage 10 communicating with the supply pipe 6. A collar-shaped valve body 12 that is vertically movable is mounted below the backflow passage 11. This valve body 12 is lightly biased upward by a spring 13, and its upper limit is regulated by a stepped portion 14 provided on the shaft portion 9a. Further, the spring 1 is attached to the lower end of the shaft portion 9a.
The collar 15 for receiving the lower end of 3 is attached, and
A flow path 17 communicating between the spring chamber 16 and the lower plunger side is formed in the lower half of the shaft portion 9a.
An upper end opening 17a is formed so as to communicate with the backflow passage 11 when the valve body 12 is moved downward by a certain amount or more.

次に、上記ポンプ３の作動を説明する。Next, the operation of the pump 3 will be explained.

カム４によってプランジャー側の燃料加圧が行われると
、送出弁９は第２図の状態のままバネ８に抗して上昇し
、弁体１２が弁座１８を通過することによって加圧燃料
が送出路１０に送り出される。When the cam 4 pressurizes the fuel on the plunger side, the delivery valve 9 rises against the spring 8 while remaining in the state shown in FIG. is delivered to the delivery path 10.

燃料圧送が終了してプランジャー側の圧がなくなると、
送出弁９かバネ８によって下降されて弁座１８に接当し
閉弁される。この場合、ノズル側の噴射弁閉弁作動に伴
って供給管内に圧力波が生しるか、この圧力は流路１１
を介て弁体１２に作用するため、弁体１２かバネ１３に
抗して下方に後退し、管内圧力が吸収される。圧力波か
強力な場合には弁体１２か大きく後退して軸部９ａの開
口１７ａを越え、管内圧力は流路１１、開７口１？ａ、
及び流路１７を介してプランジャー側に逃がされる。When the pressure on the plunger side disappears after the fuel is pumped,
The delivery valve 9 is lowered by the spring 8 and comes into contact with the valve seat 18 to be closed. In this case, a pressure wave is generated in the supply pipe as the injection valve closes on the nozzle side, or this pressure is
, the valve body 12 retreats downward against the spring 13, and the pressure inside the pipe is absorbed. If the pressure wave is strong, the valve body 12 will move back significantly and exceed the opening 17a of the shaft portion 9a, and the pressure inside the pipe will be reduced to the flow path 11 and the opening 7 opening 1? a,
and is released to the plunger side via the flow path 17.

〈効　果〉 以上説明したように、本発明によれば噴射終了時に供給
管内に発生した圧力波を弁体の後退変位によって吸収す
ることができ、二次噴射を確実に阻止することかでとる
。<Effect> As explained above, according to the present invention, the pressure wave generated in the supply pipe at the end of injection can be absorbed by the backward displacement of the valve body, and the pressure wave can be absorbed by reliably preventing secondary injection. .

又、供給管圧を正常に保持でき、噴射率を高く保つこと
かできる。Moreover, the supply pipe pressure can be maintained normally and the injection rate can be maintained high.

【図面の簡単な説明】[Brief explanation of the drawing]

図面は本発明の実施例を示し第１図は燃料噴射系の全体
構成図、第２図は燃料噴射ポンプの送出部を示す拡大断
面図である。 ６・・・燃料供給管、　訃・・バネ、　９・・・送出弁
、１１・・・流路、１２・・・逆流用弁体。The drawings show an embodiment of the present invention, and FIG. 1 is an overall configuration diagram of a fuel injection system, and FIG. 2 is an enlarged sectional view showing a delivery section of a fuel injection pump. 6...Fuel supply pipe, butt...Spring, 9...Delivery valve, 11...Flow path, 12...Reverse flow valve body.

Claims (1)

【特許請求の範囲】[Claims] １、燃料加圧によって開動され、バネ８で閉動される送
出弁９に、燃料供給管６側からの燃料逆流を許す流路１
１を形成するとともに、送出弁９の閉弁状態における燃
料供給管６の内圧上昇に伴って後退移動して送出弁９内
への燃料逆流を許す逆流用弁体１２を送出弁９に装備し
たことを特徴とする燃料噴射ポンプ1. A flow path 1 that allows backflow of fuel from the fuel supply pipe 6 side to the delivery valve 9 that is opened by pressurizing the fuel and closed by the spring 8.
The delivery valve 9 is equipped with a backflow valve body 12 which moves backward as the internal pressure of the fuel supply pipe 6 increases when the delivery valve 9 is closed, thereby allowing fuel to flow back into the delivery valve 9. A fuel injection pump characterized by
JP10707084A 1984-05-25 1984-05-25 Fuel injection pump Granted JPS60249664A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10707084A JPS60249664A (en) 1984-05-25 1984-05-25 Fuel injection pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10707084A JPS60249664A (en) 1984-05-25 1984-05-25 Fuel injection pump

Publications (2)

Publication Number Publication Date
JPS60249664A true JPS60249664A (en) 1985-12-10
JPH0256511B2 JPH0256511B2 (en) 1990-11-30

Family

ID=14449722

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10707084A Granted JPS60249664A (en) 1984-05-25 1984-05-25 Fuel injection pump

Country Status (1)

Country Link
JP (1) JPS60249664A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0405753A2 (en) * 1989-06-28 1991-01-02 General Motors Corporation Fuel-injection pump with reverse flow venting
US5287838A (en) * 1993-02-26 1994-02-22 Caterpillar Inc. Compact reverse flow check valve assembly for a unit fluid pump-injector
US5315978A (en) * 1992-03-25 1994-05-31 Mitsubishi Jidosha Kogyo Kabushiki Kaisha Fuel injection system
US5715795A (en) * 1995-09-25 1998-02-10 Robert Bosch Gmbh Fuel injection apparatus for internal combustion engines
EP0855504A1 (en) * 1997-01-28 1998-07-29 Lucas Industries Public Limited Company Valve

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56110556A (en) * 1980-02-05 1981-09-01 Nippon Denso Co Ltd Discharge valve for fuel injection pump of internal combustion engine
JPS5865966A (en) * 1981-09-25 1983-04-19 ロ−ベルト・ボツシユ・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング Fuel injection pump for internal combustion engine

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56110556A (en) * 1980-02-05 1981-09-01 Nippon Denso Co Ltd Discharge valve for fuel injection pump of internal combustion engine
JPS5865966A (en) * 1981-09-25 1983-04-19 ロ−ベルト・ボツシユ・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング Fuel injection pump for internal combustion engine

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0405753A2 (en) * 1989-06-28 1991-01-02 General Motors Corporation Fuel-injection pump with reverse flow venting
US5315978A (en) * 1992-03-25 1994-05-31 Mitsubishi Jidosha Kogyo Kabushiki Kaisha Fuel injection system
US5287838A (en) * 1993-02-26 1994-02-22 Caterpillar Inc. Compact reverse flow check valve assembly for a unit fluid pump-injector
US5715795A (en) * 1995-09-25 1998-02-10 Robert Bosch Gmbh Fuel injection apparatus for internal combustion engines
EP0855504A1 (en) * 1997-01-28 1998-07-29 Lucas Industries Public Limited Company Valve

Also Published As

Publication number Publication date
JPH0256511B2 (en) 1990-11-30

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